title: Enterohepatic helicobacter in ulcerative colitis: potential pathogenic entities?
abstract: BACKGROUND
  Changes in bacterial populations termed "dysbiosis" are thought central to ulcerative colitis (UC) pathogenesis. In particular, the possibility that novel Helicobacter organisms play a role in human UC has been debated but not comprehensively investigated. The aim of this study was to develop a molecular approach to investigate the presence of Helicobacter organisms in adults with and without UC.
  
  
  RESULTS
  A dual molecular approach to detect Helicobacter was developed. Oligonucleotide probes against the genus Helicobacter were designed and optimised alongside a validation of published H. pylori probes. A comprehensive evaluation of Helicobacter genus and H. pylori PCR primers was also undertaken. The combined approach was then assessed in a range of gastrointestinal samples prior to assessment of a UC cohort. Archival colonic samples were available from 106 individuals for FISH analysis (57 with UC and 49 non-IBD controls). A further 118 individuals were collected prospectively for dual FISH and PCR analysis (86 UC and 32 non-IBD controls). An additional 27 non-IBD controls were available for PCR analysis. All Helicobacter PCR-positive samples were sequenced. The association between Helicobacter and each study group was statistically analysed using the Pearson Chi Squared 2 tailed test. Helicobacter genus PCR positivity was significantly higher in UC than controls (32 of 77 versus 11 of 59, p = 0.004). Sequence analysis indicated enterohepatic Helicobacter species prevalence was significantly higher in the UC group compared to the control group (30 of 77 versus 2 of 59, p<0.0001). PCR and FISH results were concordant in 74 (67.9%) of subjects. The majority of discordant results were attributable to a higher positivity rate with FISH than PCR.
  
  
  CONCLUSIONS
  Helicobacter organisms warrant consideration as potential pathogenic entities in UC. Isolation of these organisms from colonic tissue is needed to enable interrogation of pathogenicity against established criteria.
authors.affiliation: Gastrointestinal Research Group, Division of Applied Medicine, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom.
authors.forename: John M
authors.initials: JM
authors.lastname: Thomson
authors.forename: Richard
authors.initials: R
authors.lastname: Hansen
authors.forename: Susan H
authors.initials: SH
authors.lastname: Berry
authors.forename: Mairi E
authors.initials: ME
authors.lastname: Hope
authors.forename: Graeme I
authors.initials: GI
authors.lastname: Murray
authors.forename: Indrani
authors.initials: I
authors.lastname: Mukhopadhya
authors.forename: Mairi H
authors.initials: MH
authors.lastname: McLean
authors.forename: Zeli
authors.initials: Z
authors.lastname: Shen
authors.forename: James G
authors.initials: JG
authors.lastname: Fox
authors.forename: Emad
authors.initials: E
authors.lastname: El-Omar
authors.forename: Georgina L
authors.initials: GL
authors.lastname: Hold
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D003093:Colitis, Ulcerative / Q000150:complications* / Q000453:epidemiology / Q000209:etiology* / Q000382:microbiology; D005260:Female; D016998:Helicobacter / Q000302:isolation & purification* / Q000502:physiology; D016481:Helicobacter Infections / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D007413:Intestinal Mucosa / Q000382:microbiology / Q000473:pathology; D007422:Intestines / Q000382:microbiology* / Q000473:pathology; D008099:Liver / Q000382:microbiology* / Q000473:pathology; D008297:Male; D008828:Microbiological Techniques; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques; D054928:Validation Studies as Topic; D055815:Young Adult